/**
* Copyright (c) 2010, Attila Magyar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*     * Redistributions of source code must retain the above copyright
*       notice, this list of conditions and the following disclaimer.
*     * Redistributions in binary form must reproduce the above copyright
*       notice, this list of conditions and the following disclaimer in the
*       documentation and/or other materials provided with the distribution.
*     * Neither the name of the Attila Magyar nor the
*       names of its contributors may be used to endorse or promote products
*       derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

package org.uftp.buffers.impl;

import java.io.IOException;
import java.io.InputStream;
import org.uftp.buffers.ReadBuffer;
import org.uftp.log.FTPLogManager;
import org.uftp.log.FTPLogger;

/**
 * A Simple unbuffered reader.
 *
 * @author Zeroflag
 */
public class SimpleReader implements ReadBuffer {

    private static FTPLogger logger = FTPLogManager.getDefaultLogger( SimpleReader.class.getName() );

    public static final int CR = "\r".getBytes()[0];
    public static final int LF = "\n".getBytes()[0];

    protected InputStream stream;

    /** Creates a new instance of SimpleReader */
    public SimpleReader() {
        this(null);
    }
        
    /** Creates a new instance of SimpleReader */
    public SimpleReader( InputStream stream ) {
        setStream( stream );
    }
    
    public void init( int bufferSize ) { /* not used */ }

    protected String readLineByChar( StringBuffer buf ) throws IOException {
                            
        boolean crFound = false;
        int c = stream.read();             
        
        while ( c != -1 ) {
            crFound = c == CR;
            buf.append( (char)c );
            c = stream.read();        
        
            if ( c == LF && crFound ) {
                buf.deleteCharAt( buf.length() -1 ); // delete CR
                break;
            }                      
        }              

        if ( c == -1 && buf.length() == 0 ) {
            return null;
        }
        
        return buf.toString();                
    }        
    
    public void setStream(InputStream stream) {
        this.stream = stream;
    }

    public String readLine() throws IOException {
        return readLineByChar( new StringBuffer() );
    }
   
}
